The present invention relates to material removing devices in general, and more particularly to improvements in rotary cutters for gouging out materials from mine faces or the like. Still more particularly, the invention relates to improvements in rotary cutters which can be used in so-called advance working machines for tunneling holes in mine faces in order to remove or to facilitate the removal of rock, ore or other solid matter.
U.S. Pat. No. 4,244,626 to Konieczny et al. discloses a rotary cutter which has a rotor carrying a number of material removing bits and being installed at one end of a driven shaft. The rotor further carries a set of spray nozzles which discharge streamlets of water to cool the bits as well as to extinguish sparks which develop as a result of penetration of bits into the material of the mine face, e.g., in an underground excavation. The nozzles receive water from cavities which are machined into the rotor.
It was further proposed to use the sprays of water which issue from the orifices of the nozzles as a means for removing the comminuted material (such as rock or ore) from the mine face. This renders it necessary to raise the pressure of water in order to ensure that the sprays will be capable of removing large quantities of comminuted material. Presently known cutters which utilize nozzles serving to facilitate or promote the removal of material from the mine face supply water at a pressure in the range of several hundred bars. Such pressure does not invariably suffice to ensure the removal of adequate quantities of comminuted material. Moreover, presently known liquid supplying systems are prone to malfunction, their parts are not readily accessible and they occupy too much space in the cutters.